From 1153565bdb728c2492294b0f92b61255e2bd9063 Mon Sep 17 00:00:00 2001
From: CHOYSEN <choysen@qq.com>
Date: Wed, 24 Feb 2021 23:04:51 +0800
Subject: [PATCH] fix(plugin-vue): fix hmr when emptying sfc file (#2142)

fix #2128
---
 packages/plugin-vue/src/handleHotUpdate.ts |  2 +-
 packages/plugin-vue/src/main.ts            | 20 ++++++++++++++++----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/packages/plugin-vue/src/handleHotUpdate.ts b/packages/plugin-vue/src/handleHotUpdate.ts
index 734c6d4a..3b3ec974 100644
--- a/packages/plugin-vue/src/handleHotUpdate.ts
+++ b/packages/plugin-vue/src/handleHotUpdate.ts
@@ -144,7 +144,7 @@ export async function handleHotUpdate({
   return [...affectedModules].filter(Boolean) as ModuleNode[]
 }
 
-function isEqualBlock(a: SFCBlock | null, b: SFCBlock | null) {
+export function isEqualBlock(a: SFCBlock | null, b: SFCBlock | null) {
   if (!a && !b) return true
   if (!a || !b) return false
   // src imports will trigger their own updates
diff --git a/packages/plugin-vue/src/main.ts b/packages/plugin-vue/src/main.ts
index d1996b08..645a5032 100644
--- a/packages/plugin-vue/src/main.ts
+++ b/packages/plugin-vue/src/main.ts
@@ -10,7 +10,7 @@ import {
 import { PluginContext, TransformPluginContext } from 'rollup'
 import { resolveScript } from './script'
 import { transformTemplateInMain } from './template'
-import { isOnlyTemplateChanged } from './handleHotUpdate'
+import { isOnlyTemplateChanged, isEqualBlock } from './handleHotUpdate'
 import { RawSourceMap, SourceMapConsumer, SourceMapGenerator } from 'source-map'
 import { createRollupError } from './utils/error'
 
@@ -71,11 +71,23 @@ export async function transformMain(
     ))
   }
 
-  const renderReplace = hasTemplateImport
-    ? ssr
+  let renderReplace = ''
+  if (hasTemplateImport) {
+    renderReplace = ssr
       ? `_sfc_main.ssrRender = _sfc_ssrRender`
       : `_sfc_main.render = _sfc_render`
-    : ''
+  } else {
+    // #2128
+    // User may empty the template but we didn't provide rerender function before
+    if (
+      prevDescriptor &&
+      !isEqualBlock(descriptor.template, prevDescriptor.template)
+    ) {
+      renderReplace = ssr
+        ? `_sfc_main.ssrRender = () => {}`
+        : `_sfc_main.render = () => {}`
+    }
+  }
 
   // styles
   const stylesCode = await genStyleCode(descriptor, pluginContext)